diff -ru libXau.org/AuFileName.c libXau/AuFileName.c
--- libXau.org/AuFileName.c	2013-09-29 22:23:56.907719612 +0900
+++ libXau/AuFileName.c	2013-09-29 22:25:17.561060783 +0900
@@ -70,8 +70,10 @@
 	if (buf)
 	    free (buf);
 	buf = malloc (size);
-	if (!buf)
+	if (!buf) {
+	    bsize = 0;
 	    return NULL;
+	}
 
         if (!atexit_registered) {
             atexit(free_filename_buffer);